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authorMark Rutland <mark.rutland@arm.com>2017-07-14 16:54:36 +0200
committerMark Rutland <mark.rutland@arm.com>2017-08-15 19:35:32 +0200
commit170976bcab073870af059b5e848c80689bd5e931 (patch)
tree92a1999396756a9b9c5c238de904989216e8fdc4 /drivers/firmware/efi/libstub
parentarm64: move SEGMENT_ALIGN to <asm/memory.h> (diff)
downloadlinux-170976bcab073870af059b5e848c80689bd5e931.tar.xz
linux-170976bcab073870af059b5e848c80689bd5e931.zip
efi/arm64: add EFI_KIMG_ALIGN
The EFI stub is intimately coupled with the kernel, and takes advantage of this by relocating the kernel at a weaker alignment than the documented boot protocol mandates. However, it does so by assuming it can align the kernel to the segment alignment, and assumes that this is 64K. In subsequent patches, we'll have to consider other details to determine this de-facto alignment constraint. This patch adds a new EFI_KIMG_ALIGN definition that will track the kernel's de-facto alignment requirements. Subsequent patches will modify this as required. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk>
Diffstat (limited to 'drivers/firmware/efi/libstub')
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index b4c2589d7c91..af6ae95a5e34 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -11,6 +11,7 @@
*/
#include <linux/efi.h>
#include <asm/efi.h>
+#include <asm/memory.h>
#include <asm/sections.h>
#include <asm/sysreg.h>
@@ -81,9 +82,10 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
/*
* If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a
* displacement in the interval [0, MIN_KIMG_ALIGN) that
- * is a multiple of the minimal segment alignment (SZ_64K)
+ * doesn't violate this kernel's de-facto alignment
+ * constraints.
*/
- u32 mask = (MIN_KIMG_ALIGN - 1) & ~(SZ_64K - 1);
+ u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1);
u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ?
(phys_seed >> 32) & mask : TEXT_OFFSET;